TRENTON – High-profile Republicans were adamant Sunday that Gov. Chris Christie should not resign from his post as chairman of the Republican Governors Association following a former ally’s claim that there is evidence Christie knew about an apparently politically motivated traffic jam earlier than he has said.

The support from former New York City Mayor Rudy Giuliani, Louisiana Gov. Bobby Jindal and Wisconsin Rep. Paul Ryan put Republicans on the offensive and the Democratic chairman of a state legislative committee investigating the September lane closures near the George Washington Bridge on the defensive the day Christie’s state hosts the Super Bowl.

Also Sunday, a member of Christie’s administration who was subpoenaed by lawmakers investigating the lane closings confirmed she had resigned.

Christina Genovese Renna left the governor’s office Friday, according to her lawyer.

Renna had reported to ousted Deputy Chief of Staff Bridget Kelly, who apparently set the lane closings in motion with an email saying “time to cause some traffic problems in Fort Lee.”

Christier, has been going about Super Bowl ceremonial duties and has not taken questions about the scandal in recent days.

He planned to watch Sunday’s game with his family from a luxury box at MetLife Stadium.

Giuliani, appearing on CBS’ “Face the Nation” took aim at the credibility of two figures central to the scandal: John Wisniewski, who’s leading the investigative probe, and David Wildstein, the former Christie loyalist who as an executive at the Port Authority of New York and New Jersey last year ordered the lane closures after receiving Kelly’s email, as someone with less than pure motives.

He said Wildstein “wants somebody else to pay his legal bills and he can’t get them paid unless the governor is responsible.”

The unannounced lane closures caused massive gridlock in Fort Lee in September. New Jersey legislators are investigating whether Christie aides engineered the lane closures to send a message to the town’s Democratic mayor.

The U.S. Attorney’s office is also investigating.

Friday, Wildstein’s lawyer wrote a letter to the Port Authority saying evidence exists that Christie knew about the traffic jams in Fort Lee as they happened.

He did not disclose any evidence in the letter.

Giuliani said Wisniewski, a Democratic assemblyman, is prejudiced and has ulterior motivations as a “guy who’d like to be governor.”

Ryan, appearing on ABC’s “This Week,” described Wildstein’s allegations as “one person’s word against the other” and said, “Nothing has been proven and you always give a person the benefit of the doubt in those kinds of situations.”

Jindal, last year’s RGA chairman, said Democrats who have called for Christie to step down from the RGA don’t understand the organization or the role of its chairman.

“The reality is within RGA, no one governor is more important than the other,” he said.